Slip-ring for dynamo-electric machines.



IN.y GSCHEIDLEN.

SLIP RING FOR DYNAMO ELECTRIC MACHINES.-

APPLlcATmN FILED MAYza. 1914 1,243,286. Patented oct. 16,1017.

Eff 729:3 72,75

5 I ff' I k/7/\ i721 fa/63pm# @MAQ WW M WILHELM'. GSCHEIDLEN, 0F BERLIN-SCHMABGENDOBF, GERMANY, ASSIGNOB 'IO SIEmS-SCHUCKEBTWEBKE, G. M. B. TION QF.GEBMANY. i

H., F BER-LIN, GERMANY, A CORPORA- SLIP-RING FOR DYNAMO-ELECTBIC MACHINES.

Specification of Letters Patent.

Application led 'Hey 28, i914. Serial No. 841,637.

. To all lwhom it may concern:

- Be it known that I, WILHELM GscHEm- LEN, a German citizen, and resident of Berlin-Schmargendorf, Germany,have invented certain new and useful Improvements in Slip-Rings `for Dynamo-Electric Machines, of which the following is a specification.

This invention relates to a novel slip-ring construction for dynamo-electric machines, preferably for high-speed dynamos, such as alternating current turbo-generators, high speed polyphase slip-ring motors, or unipolar dynamos, and has for. its object primarily to provide a slip-ring for machinery of this kind which consists of a material of high conductivity and at the same time possesses great tensile strength in its peripheral direction.

In order to meet the requirements of sliprings for high-speed dynamo-electric machinery as regards safety in service, it has been ordinary practice to employ material of very high tensile strength, permitting a suciently great safety factor. Materials possessing these qualities, however, have the characteristics of being vof relatively poor conductivity, resulting in high `ohmic losses especially in case of machinery for large current strength as employed in electrochemical work. Also by reason of electrolytical phenomena troubles are liable to occur, for instance copperI will be carried o from the negative copper brushes and deposited upon the surface of a slip-ring, this deposited copper on account of its unsuited structure resulting into a heavy sparking. By my invention, I obviate the aforementioned difficulties by employing as material for slip-rings a metal-strip, ribbon or band which is wound on edge to form a cylindrical spiral with firmly adjacent turns. slip-ring of such construction will have a considerably higher tensile strength in peripheral direction than can be obtained in case the ring is made from cast or pressed material.

The accompanying drawings show in a diagrammatic view a few constructions for slip-ringsaccordingtomyinvention. Figure 1 is a cross-section through a slip-ring acribbon or cording to my invention, Fig. 2 shows an arrangement whereby the slip-ring of Fig. l is supported by an interior ring from which the current is taken off, Fig. l3 shows the slip-ring of Fig. 1 comprising an interior supporting ring and a further pressure device for compressing the several turns of the slip-ring, Fig. 4: the same arrangement as shown in Fig. 3 withthe addition of a stop serving to prevent tangential displace- -ment of the ends of the helically wound metal strip forming said slip-ring and Fig. 5 an arrangement, wherein said stop of'Fig. 4 is substituted by a key serving to also prevent the peripheral displacement of the slip-ring 'as a whole relatively to the holding devices therefor.

A slip-ring made according to this invention is/therefore, as for instance shown in Fig. 1, wound edgewise from a metal-strip, band in a number of turns s, so as to form a ring-shaped-body which may further be mechanically reinforced by means of any kind of mechanical connection between the several turns of the windings. The free ends of the cylindrical helix thus formed may further be protected against the action of the centrifugal force by special fastening or holding devices. As regards the material' for the present slip-ring, I prefer to use copper in case the material of the brush is made from copper, in order to prem vent eventual electrolytical troubles' which are caused by using in an electrical circuit diiferent metals in contact with each other.

A further feature of this invention consists in devising means kfor carrying oi the current from the interior of the ring for making connection vwith the windings of the rotary part of the dynamo. For this purpose/I provide an electrically conductive interior ring which serves for the fastening of the conductors carrying oi the current from the slip-ring proper. Fig. 2 of the drawing shows the slip-ring proper `comprising a numy ber of turns of a metal strip s wound on edge, an interior supporting ring 11 and the conductor a for carrying o the current from said ring Another feature of my invention consists Patented oct. 16, 191ein employing means for suppressing the effect of centrifugal force upon the several turns of the slip-ring. As the windings in the middle part of the ring cannot immediately follow the centrifugal force but only change their form by relative displacement in tangential direction, this tangential pull will be found especially active at the ends of the windings, which besides will be subject to a strain in radial direction, In order to prevent the ends of the helix from being thrown out in radial direction by centrifugal force, according to the arrangement of Fig. 3 retaining rings 71.1 and h2 are employed which overlap the outer turn or turns of the helix as shown in the drawing. These retaining rings while preventing the radlal displacement of the ends of the windings, will not sufiiciently prevent their relative displacement in tangential direction. For preventing this latter displacement, as shown in Fig. 4, holdin pins p are employed which are fastenev to the supporting rings h1 and it, or to the interior ring z' or to both by arranging said holding pins near the interior periphery of the slip-ring to provide a stop for the peripheral motion of the ends of the turns of the metal strip,

A preferred arrangement for preventing the several turns to be displaced relatively to each other and relatively to the supporting ring is shown in Fig. 5 and consists of a key f which preferably extends entirely across the width of the slip-rin and which may be fastened in any desire manner to the interior ring without being necessarily strained by the tendency of the turns of the ring to undergo during service a peripheral displacement with respect to each other.

In order to secure a firm contact all over Y the contacting surface between the adjacent lis turns, it is evident that after the winding of the metal strip the same must be of rectangular cross-section. In view of the fact that during the winding the cross-section of the metal strip will change, it is necessary that the cross-section of the strip be trapezoidal in its original straight condition.

As regards the process of making the ring-body proper, it may be remarked that y for small cross-sections of the strip the saine metal strip in the form of a helix having its turns on edge with respect'to the axis.

3. A slip-ring for dynamos comprising a metal strip disposed on edge in helical turns, and holding means for holding said turns in position during service.

et. A slip-ring for dynamos comprising a metal strip disposed on edge in a number of adjacent helical turns, and a solid conductive ring interiorly of said helical turns and in conductive contact therewith.

5.' A slip-ring for dynamos comprising a metal strip which is disposed on edge in the forni of a helix, and holding means for said strip for preventing peripheral displacement of the turns thereof.

6. A slip-ring for dynamos com rising a metal strip which is disposed on e ge in the form of a helix with adjacent turns, a solid conductive sup orting ring for said metal strip, and holding means for preventin relative displacement between the severa turns of said strip and between said strip and said supporting ring.

`7. A slip-ring for dynamos comprising a metal strip which is disposed' on edge in the form of a helix with adjacent turns, a solid conductive supporting ring for said metal strip and holding means for preventin relative displacement between the severa turns of said strip and between said strip and said supporting ring, and retaining rings for holding together said helical strip in axial direction.

8. A slip-ring for dynamos comprising a metal strip which is disposed on edge iny adjacent helical turns, a conductive supporting ring for said helicalmetal strip, a pair of retaining rings for holding together said metal strip inthe axial direction of said helix, holding means for preventing displacement between the several turns of said strip as a whole relatively to said supporting ring, and retaining rings overlapping the outer turns of said metal strip for preventing radial displacement thereof.

9. A slip-ring for dynamos comprising a metal strip which disposed on edge in the form of a helix with firml adjacent turns, an interior supporting ring conductively contacting with said metal strip and unitary holding means for preventing relative displacement between the several turns of said strip and of said strip as a whole relatively to saidsupporting ring, said conductive su porting ring being adapted to receive t e connections for leading off the current from said slip-ring.

10. A slip-ring for dynamos comprising a metal strip which is disposed on edge in the form of a helix with firmly adjacent turns, an interior solid ring in conductive contact with said metal strip, unitary holding means for preventing re ative displacement be tween the several turns of said strip and of said strip as a whole relatively to said y rection,

supporting ring, and retaining rings for holding together said strip in axial disaid retaining rings overlapping the end of said helical strip and Said conductive supporting rings being adapted to receive the connections for leading olf the current from said slip-ring.

In testimony-whereof I have hereunto set my signature 1n the presence of two subscribing Witnesses.

WILHELM GSCHEDLEN. Witnesses:

WOLDEMAR HAUPT, HENRY HASPER. 

